Push-pull pneumatic tube system

ABSTRACT

The push-pull pneumatic tube system includes two terminals connected together by a single tube. One terminal is selectively subjected to a positive or negative pressure in order to push the carrier to the remote terminal or to pull the carrier to the near terminal. A simple spring gravity or friction held door may be used on the receiver part of the near terminal without danger of its being blown open, by providing a bypass operative in response to the existence of positive air pressure.

United States Patent n51 3,659,809

Cook [451 May 2, 1972 54) PUSH-PULL PNEUMATIC TUBE FOREIGN PATENTS ORAPPLICATIONS SYSTEM [72] Inventor: Ross Cook, 85 Eastfield Drive,Rolling Hills, Calif. 90274 [22] Filed: Aug. 5, 1970 [21] Appl. No:61,259

[521 U.S.Cl..... ...243/19,243/2,243/24 [51 1 Int. Cl v i v ..B65g 51/32{58] Field 0! Search ..243/2, 24, 19

[50} References Cited UNITED STATES PATENTS 3,282,531 11/1966 Stewart..243/19 1,813,487 7/1931 Emerson ..243/19 Germany ..243/2 Germany..243/19 Primary Examiner1-larvey C. Homsby Attorney-Flam & Flam [57]ABSTRACT The push-pull pneumatic tube system includes two terminalsconnected together by a single tube. One terminal is selectivelysubjected to a positive or negative pressure in order to push thecarrier to the remote terminal or to pull the carrier to the nearterminal. A simple spring gravity or friction held door may be used onthe receiver part of the near terminal without danger of its being blownopen, by providing a bypass operative in response to the existence ofpositive air pressure.

13 Claims, 5 Drawing Figures Patented May 2, 1972 3 Sheets-Sheet 2fxvvs/vroe. Boss Coax J'A 1 3A BACKGROUND OF THE INVENTION Thisinvention relates to a conveyor tube system especially adapted for usein a drive-in bank. One prior art approach is to use two tubes, bothsubject to vacuum, one of the tubes being used to send a carrier fromthe inside terminal cage to the outside drive-in station, and the otherbeing used to send a carrier tube from the outside drive-in station tothe inside terminal cage. This arrangement, however, is an extravagancebecause the carrier is not ordinarily sent from both stationssimultaneously. One carrier and tube, in fact, are adequate to serve allof the usual requirements. Thus, for example, the customer may transmitcash, checks and his bank book in the carrier and subsequently receiveback his bank book showing the appropriate entries; or, the customer maysend a check together with appropriate identification, and thereafterreceive the cash. Thus, the return transmission is ordinarily dependentupon first receiving the contents of the carrier. Accordingly, a singletube system should sufiice.

Two-way single tube systems have long been known. One of the twoterminals is selectively subjected to a positive or negative pressure inorder to send a carrier under pressure to the remote station and receivethe carrier from the remote station, respectively. This arrangementworks satisfactorily except for the fact that the pressure blows thedoor of the near terminal open; the door must be kept closed if adequatepressure is to be developed to send the carrier to the remote station.If the power or blower unit is located adjacent the teller's terminal,the teller can be depended upon to close the terminal door and to move alatch into position. However, in the interests of saving inside space,it is usually desirable to locate the power or blower unit outside andnear the customer terminal. But the customer cant be relied upon to movea latch into position.

The primary object of this invention is to make it possible to use asimple spring, gravity or friction held door on the outside terminal ofa push-pull system in which there is no danger of the door blowing opendespite the fact that the power unit is located adjacent the outsideterminal.

It has been proposed to use a terminal in which the door is driven by amotor to open and closed positions. To prevent injury to a hand left inthe door, a friction coupling must be provided between the motor and thedoor. Positive air pressure may overcome the friction to open the doorwith consequent loss of driving power.

BRIEF SUMMARY OF THE INVENTION In order to achieve the foregoing object,I provided a simple adapter mechanism that bypasses pressurized air fromthe receiver space closed by the door. Valves are moved into properposition in response to the existence of positive or negative pressure.On the negative pressure mode, one valve opens while another closes inorder to subject the terminal box itself to a negative pressure wherebythe carrier is impelled into the terminal space. On the positivepressure mode, a bypass is effected.

BRIEF DESCRIPTION OF THE DRAWINGS A detailed description of theinvention will be made with reference to the accompanying drawings.These drawings, unless described as diagrammatic or unless otherwiseindicated, are to scale.

FIG. 1 is a diagrammatic view of a pneumatic tube system incorporatingthe present invention.

FIG. 2 is a front elevational view of the outside of customer terminal.

FIG. 3 is a vertical sectional view taken along a plane corresponding toline 3-3 of FIG. 2.

FIG. 4 is a transverse sectional view taken along a plane correspondingto line 4-4 of FIG. 3.

FIG. 5 is a fragmentary section view similar to FIG. 3 but illustratinga modified form of the present invention.

DETAILED DESCRIPTION The following detailed description is of the bestpresently contemplated modes of carrying out the invention. Thisdescription is not to be taken in a limiting sense, but is made merelyfor the purpose of illustrating the general principles of the inventionsince the scope of the invention is best defined by the appended claims.Structural and operational characteristics attributed to forms of theinvention first described shall also be attributed to fonns laterdescribed, unless such characteristics are obviously inapplicable orunless specific exception is made.

FIG. 1 shows an inside or teller terminal 10 and an outside or customerterminal 12. A carrier (not shown) is sent back and forth between theterminals 10 and 12 through a single pneumatic tube 14. Opposite ends ofthe tube 14 connect with fittings 16 and 18 at the bottom of theterminals. An adapter box 20 to be hereinafter described forms the lowersection of the outside terminal 12.

The carrier is moved by the push-pull" method in which one of theterminals, in this instance the outside terminal 12, is subjected eitherto a positive or negative air pressure. When subject to a positive airpressure, the carrier is blown back to the inside terminal. Whensubjected to a negative air pressure, the carrier is sucked to theoutside terminal. The pressure is generated by a blower 22 having an airinlet 24 and an air outlet 26. The outlet 26, at which a relativepositive pressure is developed, can be connected to a fitting 28 at thebottom of the terminal 12 while the inlet 24 is subjected to theambient. Alternatively, the inlet 24, at which a relative negativepressure exists, can be connected to fitting 28 while the outlet 26 isconnected to the ambient. The alternate modes of connection of theblower 22 to the terminal 12 are determined by a suitable four-way valve30. The four-way valve 30 may be remotely controlled, as by suitableswitches adjacent the teller's terminal 10. It may also be controlled inresponse to the carrier being dropped into one end or the other of thetube 14.

The upper section of the customer terminal 12 is a receiver 32 (FIG. 3)in which the arriving carrier comes to rest. The receiver 32 is mountedon top of the adapter by suitable means. In order to arrive in thereceiver, the carrier C (shown in phantom lines) must pass through anantechamber A of the adapter 20 into the bottom of which the tubefitting 16 projects. A vertical partition 34 divides the the interior ofthe adapter 20 into front and rear sections, the front section being theantechamber and the rear chamber being a pressure chamber B into thebottom of which the blower fitting 28 projects.

The arriving carrier passes beyond the upper end opening 36 of the tubefitting l6 and then into the lower end opening 38 of a guide 40. Theupper end of the guide 40 is situated in the frontal part of thereceiver 32. Its forward portion is cut away to form a semicylindricalcradle part 42 for the carrier C.

A spring catch 44 is pushed rearwardly as the carrier C arrives at itsstation and then returns to hold the carrier in place where it isaccessible upon opening of a translucent access door 48. The door 48 isbiased to close. This could be done by hinging the door at the top forgravity bias. However, for best access, the door is hinged at thebottom. Accordingly, a spring 50 is provided. If desired, a magneticlatch (not shown) may be provided to impose a slight restraint againstopening.

The carrier C is caused to arrive at the station 12 by subjecting thereceiver box 32 to a vacuum or negative pressure. The negative pressureat the fitting 28 is conducted to the receiver 32 via an opening 52 atthe top of the pressure chamber B. The opening 52 is normally closed bya valve closure 54 spring mounted in the chamber B. A negative pressurein the chamber B causes the valve closure 54 to open.

The partition 34 has an opening 58 normally closed by a valve flap 60pivotally mounted in the antechamber. The flap 60 is gravity-biased toclose. Upon the existence of negative pressure in the pressure chamberB, the flap 60 snaps tightly closed. Air from the tube 14 is caused toflow in a circuit as follows: tube 14, antechamber A, receiver 32,pressure chamber B, to the blower section side. The carrier is thusdrawn to the terminal 12.

in order to return the carrier C to the teller terminal, the latch 44 isreleased by a solenoid 62. The carrier drops into the tube 14. Thefourway valve then imposes a positive pressure at the pressure chamberB. Under such circumstances, the spring mounted valve 54 remainsclosed.- The flap valve 60 is caused to swing to engage the edges of theoblique opening 38 of the guide 40. The air pressure is thus conductedto the tube 14 in a circuit that bypasses the receiver 32. The carrieris urged to move in the tube 14 while the receiver 32 is isolated fromthe positive pressure. The door 48 is not subjected to any air pressuretending to open it. Moreover, inadvertent opening of the door in no waydisrupts the operation.

As the valve 60 moves from the full-line position shown in MG. 3 to thephantom-line position, the receiver 32 is momentarily subjected to apressure surge. This surge is precluded from moving the door 48 by theaid of a surge valve 64. This valve is in the form of a resilient flapthat closes a small opening 66 at the back of the receiver 32. The valve64 has much less inertia than the door and thus opens first, preventinga pressure build-up that might open the door.

In the form of the invention shown in FIG. 5, the same adapter 20 isprovided as before. The door 102, in this instance, is moved by afriction drive roller 104. The drive roller may be operated by anelectric or pneumatic motor which may be remotely controlled. Thefriction drive roller engages a ring drive 106 attached to the door 102.A traveling carrier check 108, in the present instance, is mounted onthe ring drive 106. The door has a cradle 110 for the carrier 112. Asthe door opens, the carrier 112 is accessible. Only the friction betweenthe ring 106 and the roller 104 holds the door in closed position. Thereceiver is isolated from any positive pressure that might open the doorand break the circuit.

1 claim 1. In a pneumatic tube system of the push-pull type:

a. a pair of terminals;

b. a single tube connecting the terminals for transporting therethrougha pneumatic tube carrier in either direction between the terminals;

c. means forming a pressure chamber at one of said terminals;

d. said one of said terminals having a receiver chamber for saidpneumatic tube carrier;

c. said receiver chamber having an exterior access door normallyyieldingly held in closed position;

f. a power unit for selectively subjecting said pressure chamber to apositive or a negative pressure;

g. means operative upon the existence of a negative pressure at saidpressure chamber for establishing an air circuit including, in series,said tube, said receiver chamber and said pressure chamber; and

h. means operative upon the existence of a positive pressure at saidpressure chamber for establishing an air circuit including, in series,said pressure chamber and said tube with said receiver chamber excludedfrom the circuit.

2. The pneumatic tube system as set forth in claim 1 in which an adapterbox provides said pressure chamber at one part thereof, and provides anantechamber at another part thereof, said receiver chamber beingconnected to said adapter box to register both with said antechamber andsaid pressure chamber, said tube being connected to said antechamber;said circuit establishing means including:

a. a first check valve between said antechamber and said pressurechamber that opens in response to the existence of a positive pressurein said pressure chamber and that closes in response to the existence ofa negative pressure in said pressure chamber;

b. a second check valve between said receiver chamber and saidantechamber that opens in response to the existence of a negativepressure in said pressure chamber and that closes in response to theexistence of a positive pressure in said pressure chamber; and

c. a third check valve between said receiver chamber and said pressurechamber that opens in response to the existence of a negative pressurein said pressure chamber and that closes in response to the existence ofa positive pressure in said pressure chamber.

3. The pneumatic tube system as set forth in claim 2 in which said firstand second check valves include a common flap closure swingable in saidantechamber between a valve seat fonned about an opening between saidantechamber and said pressure chamber and a valve seat formed about anopening between said antechamber and said receiver chamber.

4. The pneumatic tube system as set forth in claim 2 together with afourth check valve between said receiver chamber and the ambient andarranged to open only in response to an excess pressure in said receiverchamber; said fourth check valve having a much lower inertia than saiddoor whereby transient pressure rise in said receiver chamber isinadequate to open said door.

5. The pneumatic tube system as set forth in claim 1 in which said dooris spring biased to close.

6. The pneumatic tube system as set forth in claim 1 in which said dooris moved to open and close by a pulley segment and a friction roller.

7. The pneumatic tube system as set forth in claim 1 in which said oneterminal is located to be accessible in a drive-in establishment, saidother terminal being located inside a building structure.

8. In a pneumatic tube system of the push-pull type:

a. a pair of terminals;

b. one of said terminals having an upper section comprising a receiverbox and a lower section comprising an adapter box;

c. said adapter box having a partition dividing said box into anantechamber and a pressure chamber;

d. a single tube extending between the terminals, one end of said tubebeing connected to the bottom of said antechamber;

e. a power unit for selectively subjecting said pressure chamber to apositive or a negative pressure;

f. said receiver box having spaced openings respectively to saidantechamber and said pressure chamber;

g. said receiver chamber having an access door normally yieldingly heldin closed position;

h. means responsive to the existence of a negative pressure in saidpressure chamber for establishing an air circuit including, in series,said tube, said antechamber, said receiver chamber and said pressurechamber; and

i. means responsive to the existence of a positive pressure in saidpressure chamber for establishing an air circuit including, in series,said pressure chamber, said antechamber and said tube with said receiverchamber excluded from the circuit.

9. The pneumatic tube system as set forth in claim 8 in which saidpressure responsive means include:

a. a first check valve between the antechamber and said pressure chamberthat opens in response to the existence of a positive pressure in saidpressure chamber and that closes in response to the existence of anegative pressure in said pressure chamber;

b. a second check valve between said receiver chamber and saidantechamber that opens in response to the existence of a negativepressure in said pressure chamber and that closes in response to theexistence of a positive pressure in said pressure chamber; and

c. a third check valve between said receiver chamber and said pressurechamber that opens in response to the existence of a positive pressurein said pressure chamber.

10. The pneumatic tube system as set forth in claim 9 in which saidfirst and second check valves include a common flap closure swingable insaid antechamber between a valve seat formed about an opening betweensaid antechamber and said pressure chamber and a valve seat formed aboutan opening between said antechamber and said receiver chamber.

11. The pneumatic tube system as set forth in claim 9 together with afourth check valve between said receiver chamber and the ambient andarranged to open only in response to an excess pressure in said receiverchamber; said fourth check valve having a much lower inertia than saiddoor whereby transient pressure rise in said receiver chamber isinadequate to open said door.

12. The pneumatic tube system as set forth in claim 9 in which said oneterminal is located to be accessible in a drive-in establishment, saidother terminal being located inside a building structure.

13. A terminal for a pneumatic tube system of the type wherein a carrieris transported either to or away from said terminal through a singletube comprising:

a receiver chamber,

an adapter chamber attached to the bottom of said receiver chamber andhaving a vertical, apertured partition dividing the adapter chamber intoan antechamber and a pressure chamber, said single tube being connectedto the bottom of said antechamber,

a carrier receiving cradle in said receiver chamber and having a carrierentrance guide extending downwardly into said antechamber in alignmentwith said single tube, the upper end of said cradle having openingspermitting air flow into another portion of said receiver chamber,

a flap valve pivotally mounted within said antechamber to swing betweena first position blocking the aperture in said partition and a secondposition blocking the bottom of said entrance guide,

a spring mounted valve attached within said pressure chamber to block anopening into said receiver chamber other portion when positive pressureis present in said pressure chamber, and to unblock said opening when anegative pressure is present in said pressure chamber,

a stop member for permitting unimpeded entrance of a carrier into saidcradle and for retaining said carrier within said cradle thereafter,

a power unit for selectively subjecting said pressure chamber to apositive or a negative pressure,

negative pressure establishing an air circuit including, in series, saidtube, said receiver chamber and said pressure chamber, thereby sucking acarrier from said tube through said antechamber and said guide into saidcradle,

release of said stop member permitting said carrier to drop into saidtube, subsequent positive pressure in said pressure chamber swingingsaid flap valve into said second position blocking air flow into saidreceiver chamber and establishing an air circuit including, in series,said pressure chamber, said antechamber and said tube, thereby urgingsaid carrier through said tube away from said terminal.

1. In a pneumatic tube system of the push-pull type: a. a pair ofterminals; b. a single tube connecting the terminals for transportingtherethrough a pneumatic tube carrier in either direction between theterminals; c. means forming a pressure chamber at one of said terminals;d. said one of said terminals having a receiver chamber for saidpneumatic tube carrier; e. said receiver chamber having an exterioraccess door normally yieldingly held in closed position; f. a power unitfor selectively subjecting said pressure chamber to a positive or anegative pressure; g. means operative upon the existence of a negativepressure at said pressure chamber for establishing an air circuitincluding, in series, said tube, said receiver chamber and said pressurechamber; and h. means operative upon the existence of a positivepressure at said pressure chamber for establishing an air circuitincluding, in series, said pressure chamber and said tube with saidreceiver chamber excluded from the circuit.
 2. The pneumatic tube systemas set forth in claim 1 in which an adapter box provides said pressurechamber at one part thereof, and provides an antechamber at another partthereof, said receiver chamber being connected to said adapter box toregister both with said antechamber and said pressure chamber, said tubebeing connected to said antechamber; said circuit establishing meansincluding: a. a first check valve between said antechamber and saidpressure chamber that opens in response to the existence of a positivepressure in said pressure chamber and that closes in response to theexistence of a negative pressure in said pressure chamber; b. a secondcheck valve between said receiver chamber and said antechamber thatopens in response to the existence of a negative pressure in saidpressure chamber and that closes in response to the existence of apositive pressure in said pressure chamber; and c. a third check valvebetween said receiver chamber and said pressure chamber that opens inresponse to the existence of a negative pressure in said pressurechamber and that closes in response to the existence of a positivepressure in said pressure chamber.
 3. The pneumatic tube system as setforth in claim 2 in which said first and second check valves include acommon flap closure swingable in said antechamber between a valve seatformed about an opening between said antechamber and said pressurechamber and a valve seat formed about an opening between saidantechamber and said receiver chamber.
 4. The pneumatic tube system asset forth in claim 2 together with a fourth check valve between saidreceiver chamber and the ambient and arranged to open only in responseto an excess pressure in said receiver chamber; said fourth check valvehaving a much lower inertia than said door whereby transient pressurerise in said receiver chamber is inadequate to open said door.
 5. Thepneumatic tube system as set forth in claim 1 in which said door isspring biased to close.
 6. The pneumatic tube system as set forth inclaim 1 in which said door is moved to open and close by a pulleysegment and a friction roller.
 7. The pneumatic tube system as set forthin claim 1 in which said one terminal is located to be accessible in adrive-in establishment, said other terminal being located inside abuilding structure.
 8. In a pneumatic tube system of the push-pull type:a. a pair of terminals; b. one of said terminals having an upper sectioncomprising a receiver box and a lower section comprising an adapter box;c. said adapter box having a partition dividing said box into anantechamber and a pressure chamber; d. a single tube extending betweenthe terminals, one end of said tube being connected to the bottom ofsaid antechamber; e. a power unit for selectively subjecting saidpressure chamber to a positive or a negative pressure; f. said receiverbox having spaced openings respectively to said antechamber and saidpressure chamber; g. said receiver chamber having an access doornormally yieldingly held in closed position; h. means responsive to theexistence of a negative pressure in said pressure chamber forestablishing an air circuit including, in series, said tube, saidantechamber, said receiver chamber and said pressure chamber; and i.means responsive to the existence of a positive pressure in saidpressure chamber for establishing an air circuit including, in series,said pressure chamber, said antechamber and said tube with said receiverchamber excluded from the circuit.
 9. The pneumatic tube system as setforth in claim 8 in which said pressure responsive means include: a. afirst check valve between the antechamber and said pressure chaMber thatopens in response to the existence of a positive pressure in saidpressure chamber and that closes in response to the existence of anegative pressure in said pressure chamber; b. a second check valvebetween said receiver chamber and said antechamber that opens inresponse to the existence of a negative pressure in said pressurechamber and that closes in response to the existence of a positivepressure in said pressure chamber; and c. a third check valve betweensaid receiver chamber and said pressure chamber that opens in responseto the existence of a positive pressure in said pressure chamber. 10.The pneumatic tube system as set forth in claim 9 in which said firstand second check valves include a common flap closure swingable in saidantechamber between a valve seat formed about an opening between saidantechamber and said pressure chamber and a valve seat formed about anopening between said antechamber and said receiver chamber.
 11. Thepneumatic tube system as set forth in claim 9 together with a fourthcheck valve between said receiver chamber and the ambient and arrangedto open only in response to an excess pressure in said receiver chamber;said fourth check valve having a much lower inertia than said doorwhereby transient pressure rise in said receiver chamber is inadequateto open said door.
 12. The pneumatic tube system as set forth in claim 9in which said one terminal is located to be accessible in a drive-inestablishment, said other terminal being located inside a buildingstructure.
 13. A terminal for a pneumatic tube system of the typewherein a carrier is transported either to or away from said terminalthrough a single tube comprising: a receiver chamber, an adapter chamberattached to the bottom of said receiver chamber and having a vertical,apertured partition dividing the adapter chamber into an antechamber anda pressure chamber, said single tube being connected to the bottom ofsaid antechamber, a carrier receiving cradle in said receiver chamberand having a carrier entrance guide extending downwardly into saidantechamber in alignment with said single tube, the upper end of saidcradle having openings permitting air flow into another portion of saidreceiver chamber, a flap valve pivotally mounted within said antechamberto swing between a first position blocking the aperture in saidpartition and a second position blocking the bottom of said entranceguide, a spring mounted valve attached within said pressure chamber toblock an opening into said receiver chamber other portion when positivepressure is present in said pressure chamber, and to unblock saidopening when a negative pressure is present in said pressure chamber, astop member for permitting unimpeded entrance of a carrier into saidcradle and for retaining said carrier within said cradle thereafter, apower unit for selectively subjecting said pressure chamber to apositive or a negative pressure, negative pressure establishing an aircircuit including, in series, said tube, said receiver chamber and saidpressure chamber, thereby sucking a carrier from said tube through saidantechamber and said guide into said cradle, release of said stop memberpermitting said carrier to drop into said tube, subsequent positivepressure in said pressure chamber swinging said flap valve into saidsecond position blocking air flow into said receiver chamber andestablishing an air circuit including, in series, said pressure chamber,said antechamber and said tube, thereby urging said carrier through saidtube away from said terminal.